SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30f53f4492dc2bf0bffe75b662f4223baa374683b8ce551369918fe319aab00b' 
  AND token = 'cdo/+tDYN6lkHu+B4Y8erKu8tO0TEYVZYQtPxBaWqhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}